Known valves of DE 100 17 323 A1 and US 2002/0040730 A1 serve for the air release from tanks during the filling operation and/or for the release of air from the tanks during driving of the vehicle. These known valves are normally set into an opening in the upper tank wall and possess at least one opening, by means of which a fuel-vapor/air mixture (in the following referred to as “gas”) is conducted into the valve and subsequently released to the atmosphere through an outlet opening, this operation being carried out, as a rule, with interposed equipment allowing scrubbing of the gas through at least one activated carbon filter. In order to prevent, that during the driving, splashing fuel does not enter into the activated carbon filter, in the housing of the air release valve is to be found an axially movable float, which, on its top side, carries a sealing element which coacts with the outlet opening. As the tank approaches being filled, the float rises simultaneously with the rising level of the fuel, with the result that it closes the outlet opening. Such a closure is brought into effect also in a case of turbulently splashing fuel during road operation. This arrangement increases inside gas pressure, with the result that reopening an outlet opening, necessarily requires considerable force. In order to compensate for this situation, floats of considerable weight have been necessary. So that such a weighty float could maintain sufficient buoyancy, a corresponding displacement means proved necessary. Air release valves with such floats, on this account, became very voluminous and called for considerable material in their manufacture. U.S. Pat. No. 5,439,023 teaches of a two stage air release valve having a sealing element. Laterally, on one side of this sealing element rests a molded on, top located hook of the float structure. Because the hook initiates one way flow, the proposal of U.S. Pat. No. 5,439,023 is, that a thereby created lever operation increases the force exercised by the float upon the sealing element. Additionally, the sealing element is penetrated by a boring of small diameter, which in turn is closed by a second sealing element. Also this arrangement, upon the opening procedure, is subjected to force loading from lever action, whereby the boring of the first named sealing element is opened. DE 102 57 223 A1 also discloses a two stage air release valve. In this valve, the float possesses on one side of its top a linked lever arm, the middle section of which arm forms a sealing element, which coacts with an outlet opening. This element is likewise penetrated by a boring of small diameter which cooperates with a top-sided projection installed on the float as a sealing element. U.S. Pat. No. 5,738,132 discloses a single stage air release valve, wherein a slot-shaped, outlet opening runs at an angle to the central axis of the valve and has a flexible strip of membrane serving as a coacting sealing elements. One end of the membrane strip is affixed to the float. Consequently, the membrane is withdrawn from the outlet opening in successive fashion during the opening operations. That is to say, in particular, withdrawn from the surrounding seat of the sealing means.